I managed to get this trophy yesterday.
I did it on Nadiri Dockyards; Easy, AI Fleet Battle with the A-Wing Rotary and everything else as standard.
What worked for me was when the imperials went on the attack first - this effectively gave me additional time instead of us attacking first and taking them out. If we attacked first, I would exit and start again.
Focus on the enemy squadron when they are attacking, switch to enemy AI when we are attacking.
My final kill count was: Enemy Squadron:33 Enemy AI:48.
Good luck, it took me about ~10 games to get it. Also, the trophy pops during the event, and not at the end when giving the match summary. This got me as I assumed it would be awarded once the match had been completed.